Improvement in friction-clutches



T; STEBIN S, improvement inFriction-Clutch.

"*wo'iwam rs. I I

Patented Oct.1,1872.

, Witnesses California, have invented an Improved Fric- .in the art or science to which it most nearly erwise, the power is reversed, the bars will tion, referenceis had to the accompanying on which it revolves.

inside of the pulley, and is keyed firmly to provide a projection, c, which lies and moves -a greater amount of surface against the rim UNITED STATES TIMOTHY STEBINS, OF SAN PATENT OFFICE.

FRANCISCO, CALIFORNIA.

IMPROVEMENT IN FRICTIONCLUTCHES.

Specification forming part of Letters Patent No. l31,795,-dated October 1, 1872.

To all whomidf inay concern: i

Be it known that I, TIMOTHY STEBrNs, of city and county of San Francisco, State of tion Clutch and I do hereby declare the following description andaccompanyin g drawing are sufficient to enableanyperson skilled appertains to make and use my said invention or improvements without further invention or experiment.

My invention relates to an improved fric-' tion-clutch, such as are employed for hoisting-pulleys, and for other like purposes, where it is necessary that the pulley shall revolve freely in one direction, and lock itself by the reverse motion immediately upon the power being removed. My friction-clutch consists ofa slotted disk, so arranged inside of a pcculiar box-pulley that bars can be placed in the slots with one end moving against the structed and applied that when the disk is revolved in one direction they will move bind against the rim, and serve as a clutch, to hold the disk in place.

In order to more fully illustrate my invendrawing'forming a part of this specification, in

A represents a hollow pulley, having a rim and one side, as shown; and B the shaft up- The side of this pulley is constructed with an interior circular ledge, 0, somewhat smaller than the diameter of the inside of the pulley, thus leaving an annular channel, d, between the rim of the ledge and the rim of the pulley A. A circular disk, E, slips down over the shaft B, so as to lie against the face of the ledge U,

the shaft. This disk is provided with one or more radial slots, ff, which extend from near its hub at g to the outer edge of the disk, as shown. These slots are made wide enoughto admit of bars hto 'lie in them. The outer ends of these bars h are bent at right angles, or otherwise formed so as to inthe channel d, while their opposite ends bear against the opposite end of the slot. The object of thus fitting the bars is to give of the pulley for frictional purposes, while the bent ends, fittingin the channel 01, steady the bars in their movements. The slots f f are so constructed that when the bars h lie fiat against one of their sides a radial line,

drawn from the center of the disk to its periphery through the slots, will pass directly through the middle of the bars; and when in this position the disk can be moved around in one direction by revolving the shaft B, the bars moving with it. The slots are wider than the bars, and the sides opposite their straight sides are curved from the inner to the outer end of the slots, thus making them wider at the rim of the disks than at the bottom or end nearest the center. The bottoms of the slots are also made upon the curve of a circle drawn from the center of the shaft,

so that when it is attempted to revolve the shaft B backward, or in the reverse direction 7 from that above mentioned, the bars will immediately bind against the rim of the pulley A, and lock the disk in its position.

A cap may be fitted over the open end of the pulley, and thus the entire movement be concealed and protected.

By this means I provide a cheap and effective friction-clutch,which cannot be fouled,

and which will prevent many accidents, by locking itself should any of the machinery connected with it give way. It is also ser-x viceable for hoist-ways, and for similar purposes.

Having thus described my invention, what im, and desire to secure by Letters Pat- 1s 1 The outer shell 'orpulley A, in combination with the radially-slotted disk E, and brake-bars h, substantially as and for the purpose above described.

2. The pulley A, having one side provided -with a ledge, 0, so as to form an annularchannel, (1, in combination with the brakebars h, having the projection i, substantially as and for the purpose above described.

3. The slots f f, having one straight and one curved side, and acurved bottom, in combination'with the brake-bars h, substantially as and i .for the purpose above described.

In witness that the above-described invention is claimed by me I have hereunto set my hand and seal.

Witnesses: T. STEBIN S. [L. s.]

BENJN. G. FABRE, GEO. H. STRONG. 

